Receive feedback about xdg_toplevel_move

As far as I understand, there currently is no way to determine whether xdg_toplevel_move is actually performing an action or if the request is being ignored. It could be ignored for several reasons (compositor does not allow for freeform surface positioning like on many mobile compositors, surface is maximized, etc).

This information would be useful to determine further steps after initiating the move (show a different cursor when move is not possible, pass the movement information further along etc).

When resizing the surface will get the resizing state, could this be expanded to also have a moving state that would be set when the toplevel is currently in the process of being moved? To make this more useful and actually do something with the events, this would probably need the added requirement on xdg_toplevel_move to not lose focus of the device when a move is not actually taking place.